fix: ensure onClose triggers on unexpected disconnections

Added channelInactive handler to MessageHandler to catch connection drops
that don't send a proper WebSocket close frame. This ensures the onClose
callback fires in all disconnect scenarios:

- Network failures
- Server crashes
- Connection timeouts
- Any scenario where the channel becomes inactive

All close events are propagated to the onClose callback, ensuring the
Realtime service's reconnection logic triggers correctly.

Author: ChiragAgg5k

templates/swift/Sources/WebSockets/MessageHandler.swift.twig

@@ -31,7 +31,16 @@ class MessageHandler {
 extension MessageHandler: ChannelInboundHandler, RemovableChannelHandler {
 
     typealias InboundIn = WebSocketFrame
-    
+
+    public func channelInactive(context: ChannelHandlerContext) {
+        let emptyData = Data()
+        if let delegate = client.delegate {
+            delegate.onClose(channel: context.channel, data: emptyData)
+        } else {
+            client.onClose(context.channel, emptyData)
+        }
+    }
+
     public func channelRead(context: ChannelHandlerContext, data: NIOAny) {
         let frame = self.unwrapInboundIn(data)
         switch frame.opcode {